Droves of doughy promise makers are expected to pack health clubs this week — part of the usual January pilgrimage to try to shed pounds — but some guys fresh to the sweat-soaked scene are destined to lose something else: their steely-eyed resolve.

Visions of puffed pecs and bulky barbells slung like bottles of water by members of their own gender can, for many men, quickly torpedo New Year’s pledges. Other males, meanwhile, simply vow to avoid entirely, they admit, what they imagine to be hubs of testosterone on parade.

Call it gym intimidation: a phenomenon not openly discussed among many non-flexing fellas – yet possibly a trend on the rise. In January, Nautilus will launch a new home-exercise tool designed solely for men. Meanwhile, Nautilus topped a recently published Forbes Magazine list of the best 2012 sports stocks (with an annual growth of 106 percent), and company officials cite, in part, the growing preference among males to pump up in private.

“More men are starting to work out at home,” said Nautilus spokesman John Fread. “When you’re going to that gym, especially if you’ve never been before, you’ve got body comparisons. Women do it. Men do it.

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“You’re looking at those people around you who may have already achieved their fitness goals, and that’s a really intimidating thing," Fread added. “Walking into a space with mirrors all the way around sort of reminds you that maybe you’re not where you want to be.”

Luke Orlando, once a lanky, high school tennis player in Texas, admits he has “experienced gym intimidation, sometimes to the point where I refrained from going at all.” In fact, when Orlando earned his driver’s license at age 16, one of the first things he intended to do was drive to a nearby health club to buy a membership. It took him nine months to make that trip. In the meantime, he hoisted weights in his garage.

“I’ve always been really skinny. I wanted to be bigger,” said Orlando, 18, today a student at the University of Texas. “I didn’t feel like I could go to the gym unless I met this minimum threshold — this unspoken threshold you needed in order to work out at the gym. I thought that you needed to be able bench (press) a certain amount before it wouldn’t be embarrassing.”

The bench-press goal he devised: 150 pounds.

But after a football-playing buddy accompanied Orlando to a public gym and walked him through several sets of exercises with weights, he began to feel more comfortable with the routine and the culture. He became a gym regular. Two years later, Orlando said he’s packed 45 pounds of muscle (175 pounds total) onto his 6-foot-1-inch frame.

The type of health club you frequent (or want to try) also can boost or lessen the intimidation factor, said Walter Meyer, a San Diego-based author who hits the gym in his home town and while on book tours.

“I also have friends who have the fear that if they are not bench pressing Volkswagens, the other guy at the gym will look down on them,” Meyer said. “I think there are many gyms in which that may be the case, (like) the serious weightlifter gyms.

“But at most chain gyms – I belong to both 24 Hour Fitness and LA Fitness – no one cares,” Meyer added. “Perhaps if there are more women present, there is less testosterone. But also I think if more of the crowd is into casual fitness rather than body building, they are less likely to pay enough attention to resent your taking up space to curl five-pound dumbbells.”

Of course, women also weather waves of intimidation while in the gym and, according to a recent study, some young women try to compensate for that by purposely exercising close to females who appear to be less fit by comparison.

"The feeling of intimidation is likely quite similar for men and women, varying in intensity, of course, depending on how extreme the (negative, self-assessing) thoughts become. But the triggers can certainly be different," said Dr. Simon Rego, director of psychology training at Montefiore Medical Center/Albert Einstein College of Medicine in New York.

Categorizing fitness-center fears by gender alone is tricky, he added, because how males and females see themselves is often influenced by culture, family and the role models in their lives.

"I would also predict that both genders would prefer to exercise near less-fit people," Rego said, "as making this type of comparison is often a useful coping strategy for dealing with difficult feelings and to help tolerate the things we can't immediately change," like our size and shape.

"People are often their own worst critics. In other words, while they may be viewed as 'intimidating' to others around them (due to some attractive part of their physical appearance), their own thoughts about themselves (and certain pieces of their own bodies that they dislike) could still lead them to feel self-conscious or intimated by others. It's not about reality - it's about what we think that shapes our reality."